Re: [boost] feature request for optional

From: David Abrahams (dave_at_[hidden])
Date: 2006-08-07 22:11:53

Sascha Krissler <boost-dev_at_[hidden]> writes:

> That's what i am doing right now.
> The messy interface differences could be smoothed out by optional<>.

It's not optional's job to make that decision.  0 is a valid pointer
value, and it's not the same thing as "no pointer value."

> If i had to implement all the interface of OptionalPointee again
> that would be a lot of duplication whether changing optional would
> be a couple of mpl::if_.  Well i will not wait for a new release of
> boost to solve my poblem anyway it is a suggestion to improve the
> genericity of the lib.

Unfortunately, it would reduce genericity.  Suddenly some types have
special values that can't be represented distinctly from an empty
optional.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com